U.S. patent number 4,555,292 [Application Number 06/580,839] was granted by the patent office on 1985-11-26 for method of forming a non-skid surface wood panel.
This patent grant is currently assigned to Thom-McI, Inc.. Invention is credited to Thomas L. Thompson.
United States Patent |
4,555,292 |
Thompson |
November 26, 1985 |
Method of forming a non-skid surface wood panel
Abstract
The present invention defines two methods of forming a
non-skid-surfaced wood panel, preferably plywood, which is treated
with various coats or layers of epoxy resin, together with a
finished surface coat of polyurethane combined with a hard-grit
abrasive material evenly spread within the surface coat, so as to
provide the non-skid substance that establishes a unique and
wear-resistant structure for areas subjected to heavy foot traffic,
the invention being particularly suitable for use on decking in
marine environments.
Inventors: |
Thompson; Thomas L. (Costa
Mesa, CA) |
Assignee: |
Thom-McI, Inc. (Balboa,
CA)
|
Family
ID: |
26099309 |
Appl.
No.: |
06/580,839 |
Filed: |
February 16, 1984 |
Current U.S.
Class: |
156/279; 428/328;
52/181; 156/258; 156/315; 238/14; 427/202; 428/143; 52/796.1;
114/263; 156/295; 156/330; 404/19; 427/203; 427/205; 428/212 |
Current CPC
Class: |
B32B
13/10 (20130101); E04F 15/02 (20130101); E04F
15/04 (20130101); B32B 27/20 (20130101); E04F
15/02172 (20130101); Y10T 428/24372 (20150115); Y10T
156/1066 (20150115); Y10T 428/256 (20150115); B32B
2255/08 (20130101); B32B 2255/26 (20130101); Y10T
428/24942 (20150115) |
Current International
Class: |
B32B
13/00 (20060101); B32B 13/10 (20060101); E04F
15/02 (20060101); E04F 15/04 (20060101); B32B
031/00 () |
Field of
Search: |
;156/257,295,258,315,279,330 ;114/263 ;238/14 ;404/19 ;52/811,181
;428/212,328,143 ;427/202,205,203 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
50-8479 |
|
Apr 1975 |
|
JP |
|
1560692 |
|
Feb 1980 |
|
GB |
|
Primary Examiner: Gallagher; John J.
Attorney, Agent or Firm: LoJacono; Francis X.
Claims
I claim:
1. A method of forming a non-skid-surfaced plywood panel having a
permanent but flexible bond between said plywood and the non-skid
elements thereof, wherein the method comprises the steps of:
providing a sheet of plywood having substantially flat opposite
surfaces;
applying to each of said surfaces a first coat of low-viscosity,
catalized, epoxy resin so as to penetrate and seal said
surfaces;
applying a second coat of a catalyzed epoxy resin to the upper
surface of said plywood panel prior to the drying of said first
coat of epoxy resin, said second coat having a higher viscosity
than said first coat;
providing a fiber/cement panel having substantially the same
configuration as said plywood panel;
applying a third coat consisting of the same catalyzed epoxy resin
used in said second coat to one surface of said fiber/cement
panel;
placing said coated surfaces of each panel into opposing engagement
with each other;
applying pressure to said panels, whereby excess epoxy material is
forced from between said panels;
allowing said epoxy between said panels to dry;
applying at a predetermined thickness a fourth coat of pigmented
polyurethane material to form a surface layer over the exposed
surface of said fiber/cement panel;
disseminating a hard grit material over said fourth coat while said
polyurethane material is still in a wet stage, said grit material
being of a size greater than the thickness of said fourth coat, so
as to allow a portion of said grit to be exposed above the surface
of said fourth coat; and
allowing said polyurethane coat to dry, thereby securing said grit
material within said fourth coat.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a structural panel, and more particularly
to a panel constructed preferably from a section of plywood that is
processed so as to establish a unique method of forming a
non-skid-surfaced wood panel, wherein the finished product provides
a weatherproof and wear-resistant structure for areas subjected to
heavy foot traffic, such as marine decking.
2. Description of the Prior Art
The invention as disclosed herein is particulary suitable for
solving various and difficult problems associated with surface
structures which are designed for heavy pedestrian traffic,
especially with respect to those surfaces associated with
marine-dock systems and their surrounding structures. Several types
of walking surfaces have been employed for this purpose, but with
limited success. At present, there are two widely used surface
materials, one being made from wood products and the other being
constructed from relatively thin concrete or cement slabs. Wood
surfaces are generally formed from a multiplicity of juxtaposed
plank members positioned transversely across the deck or
walkway.
A dock structure or walkway formed from cement slabs is usually
defined by elongated rectangular slab members having a thickness of
from one to two inches. Even though cement surfaces are becoming
more popular over wood surfaces in the construction of marinas and
related floating-dock structures, there are two inherent problems
that prevail. One of these is that concrete slabs are very heavy
and add considerable weight to an already large and heavy
structure, making them cumbersome and difficult to handle; and the
other is that cement slabs used for dock fingers and walkways are
not resilient, and have a tendency to crack when subjected to
twisting and flexing in turbulent water caused by adverse weather
conditions.
Hence, it can be readily understood from the following disclosure
of the present invention that, when the end product thereof is
employed, the above-mentioned problems are overcome.
SUMMARY AND OBJECTS OF THE INVENTION
The present invention has for an important object to provide a new
and unique method of forming a non-skid-surfaced wood panel that
can be readily employed as a structural walkway or decking for
marinas and like areas.
Another object of the present invention is to provide a method of
forming a non-skid-surfaced wood structure that is lightweight and
wear-resistant, and capable of allowing heavy pedestrian traffic,
while eliminating the above-mentioned problems that are inherent in
the known surface structures.
Still another object of the invention is to provide a non-skid,
preferably plywood, panel structure that is lightweight, durable
and resilient, so that it can flex without cracking.
Another object of the invention is to provide a non-skid-surfaced
plywood structure wherein the plywood is sealed on both opposing
surfaces by applying a low-viscosity coat of catalyzed epoxy resin
which is allowed to soak into the wood fibers. Immediately
following the first application, a second coat of thickened epoxy
resin of approximately 20 to 30 mils is applied. This coat is
allowed to dry for approximately one hour, whereupon a third coat
of pigmented polyurethane is then applied to the epoxy surface, so
as to attain a thickness of approximately 30 mils. While this third
coat is still quite wet, and before it develops a skin, a very hard
grit material such as aluminum oxide is evenly broadcast over the
wet surface. The grit is provided with the proper coarseness so as
to establish a sandpaper-like surface.
A still further object of the invention is to provide a method of
this character that can be used for forming a non-skid surface
structure that can be readily employed either as a permanent or a
temporary walkway for pedestrian traffic at building sites, and for
replacement and/or repair of worn walkways or decks that would
otherwise need to be reconstructed.
Other features, objects and advantages of the instant invention
will be obvious to persons skilled in the art from the following
detailed description of two embodiments, accompanied by the
attached drawings, in which identical reference numerals will refer
to like parts in the various views.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring more particularly to the accompanying drawings, which are
for illustrative purposes only:
FIG. 1 is a cross-sectional view of a piece of plywood, indicating
the first step of applying a thin viscous coat of sealer
material;
FIG. 2 is a cross-sectional view of the wood pieces, illustrating
the second step of applying a thickened coat of an epoxy
material;
FIG. 3 is still another similar cross-sectional view, showing a
third step wherein a third thick coat is applied thereto;
FIG. 4 is another cross-sectional view, illustrating the last step
of applying a grit material to the surface thereof; and
FIG. 5 is a cross-sectional view, illustrating an additional
embodiment of the invention which uses a sheet of fiber/cement
therewith.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to FIGS. 1 through 4, there are shown
enlarged cross-sectional views representing a non-skid surfaced
panel 10 illustrated in such a manner as to indicated sequentially
the several necessary steps for producing the panel.
As previously mentioned heretofore, there are several areas of
application for which the present invention is well suited, even
though its main purpose is to establish a non-skid decking in and
about waterfront areas or related environments, and more
particularly in connection with decking for marine-dock structures.
However, it is readily apparent that, after understanding the end
results of the present invention and its unique advantages, other
uses for floorings, walkways and even roadways, can be
established.
FIG. 1 shows a wood panel 10 which is formed preferably from a
plywood structure having a thickness of between 1/4" to 21/2", with
a specification requiring a 11/8" thick Grade CC exterior plywood
panel which is pressure-preservative treated.
It is important to note, however, that other wood products, such as
planks, boards, etc., can be substituted for the plywood which is
used in the description because it is considered to be the
preferred embodiment of the present invention.
The purpose of the particular method of forming the end product of
the non-skid-surfaced panel is to provide a permanent but flexible
bonding between the plywood and the non-skid elements thereof.
Accordingly, the present invention defines a plywood panel of a
generally rectangular configuration including flat opposite
surfaces having the approximate dimensions of a typical 4'.times.8'
panel. It is contemplated that each panel will include a
tongue-and-groove arrangement. That is, a tongue 12 is formed along
one longitudinal edge of panel 10, and a matching groove 14 is
formed along the oppositely disposed longitudinal edges. This
establishes a contiguous sealed connection between adjacent panels
when they are structurally placed.
Once the plywood panel is selected and defined, a coat of catalyzed
eopxy resin 16 having a low viscosity is applied to both flat
surfaces 18 and 20 of panel 10. In other words, a catalyzed epoxy
resin, indicated by the dots 16, must be applied in a thin liquid
state, so as to penetrate within the surfaces 18 and 20, thus
soaking into the wood fibers and readily sealing these respective
surfaces.
The next step is to immediately apply a second coat of the same
type of catalyzed epoxy resin. However, this second coat 22 is much
thicker in viscosity and is formed having a thickness of between 10
to 30 mils. In order to aid in the bonding strength of epoxy layer
22, there is added thereto a sufficient amount of ground fiberglass
(cabosil) which moreover provides a controlled viscosity of the
epoxy resin. The second coat 22 is applied only to surface 18,
which defines the upper or outer surface, and is then allowed to
harden together with the first thin coat 16. Thus, a very strong
bond is established between the second thick coat 22 and the
saturated wood fibers on surface 18. The time required for the
hardening of the second coat 22 can vary, but generally it takes
about one hour to dry hard under normal, ambient, room temperature,
although the plywood at this time can, if desired, be subjected to
a predetermined controlled temperature, whereby the hardening time
will be set under a selective temperature-controlled
environment.
After the hardening of second coat 22, a third coat 24 is applied.
This coat is preferably a pigmented polyurethane material that is
spread or rolled over coat 22 and is applied having a thickness of
between 10 to 40 mils, but preferably 30 mils. The thickness of
this coat is normally determined by the size and type of abrasive
material that is combined therewith, the grit size being between
No. 30 and No. 60. That is, while the polyurethane coat 24 is still
very wet, and before it develops a skin-like surface, an overlay of
very hard grit substance 26 is evenly spread or disseminated over
the wet layer of polyurethane. It is preferred that grit 26 be a
No. 46 size of aluminum oxide, whereby a 30-mil thickness to layer
24 would be achieved so as to allow the very sharp edges of the
aluminum-oxide, sand-like particles to extend slightly above the
surface of coat 24. Thus, the greater part of each grit particle is
submerged and held in place by the proper thickness of the
polyurethane material. It should be noted that other grit materials
can also be used as an overlay under specific environmental
conditions. Various materials such as silica sand and crushed
walnut shells can be employed to provide a non-skid-coating
base.
A second embodiment is disclosed in FIG. 5, wherein a fiber/cement
panel 30 having the same rectangular configuration as that of
plywood panel 10 is placed over the second epoxy layer 22, thereby
bonding the fiber/cement panel to the plywood panel. The
fiber/cement panel 30 is relatively thin and has a thickness of
approximately 1/8". This panel generally consists of 36 percent
Portland cement; 30 percent crushed limestone; 20 percent Possolan
Volcanic ash; and 14 percent cricotile asbestos fiber (silky) 5/8"
long. This particular composition is highly resistant to salt
corrosion, has excellent chemical resistance, and has resilient
qualities to prevent cracking when subjected to constant movement,
particularly when used as a walk surface on a floating-dock
structure supported in a body of water, in which case the panels
bend and twist to some extent.
Accordingly, the following additional steps are required when the
fiber/cement panel is employed:
After applying the second coat of thicker cabosil-epoxy resin 22 to
the plywood surface 16, this same thicker resin is also applied to
the underside 29 of the fiber/cement panel 30. While both
fiberglass-epoxy resin coats are still wet, the fiber/cement panel
30 is positioned over the plywood panel, allowing the two epoxies
to commingle as one coating 22a.
At this time, the two attached panels 10 and 30 are placed in a
press, whereby approximately 100 p.s.i. pressure is applied, thus
forcing out the excess epoxy material and establishing a very thin
bonding line between the two panels.
Once this is accomplished, the pigmented polyurethane-material coat
is applied to the upper surface 32 of panel 30. Again, the
thickness of the coat is determined by the size and type of
abrasive material that is applied thereafter.
After panel 30 is bonded to plywood panel 10, polyurethane layer 24
is applied, as described above, together with the appropriate grit
material 26.
It should be noted, however, that on some occasions the grit
(aluminum oxide) will prove to be too abrasive for use as intended,
in which case it will then be necessary to apply a second coat of
polyurethane so as to reduce the sharpness of the abrasive
particles. The second coat will further cover the grit surfaces to
the level where only the top points of the grit are protruding from
the surface, or the points might be slightly covered in the case of
lower-lying grit particles. As foot-traffic wear takes place, some
of these lower particles of grit will wear through the top-cover
coat and provide part of the non-skid effect. Furthermore, the
second coat will also trap any loose grit that, for some reason,
might not be well fastened into the first coat. A second benefit is
derived from employing a second finished polyurethane coat--which
is that the color of the surface can be precisely controlled.
The invention and its attendant advantages will be understood from
the foregoing description; and it will be apparent that various
changes may be made in the form, construction and arrangement of
the parts of the invention without departing from the spirit and
scope thereof or sacrificing its material advantages, the
arrangement hereinbefore described being merely by way of example;
and I do not wish to be restricted to the specific form shown or
uses mentioned, except as defined in the accompanying claims.
* * * * *